packages: ship galaxy.tool_source_store in galaxy-app; search reads config directly

The packages/app tree links each galaxy subpackage explicitly and
tool_source_store was never added, so the built wheel lacked the package
and per-package mypy resolved its imports as Any (surfacing as
'Returning Any' in LazyToolboxSearch.search).

lib/galaxy/tools/search/__init__.py

@@ -166,11 +166,11 @@ class LazyToolboxSearch(ToolBoxSearch):
             ToolWhooshIndex,
         )
 
-        index_dir = whoosh_dir_for_store(getattr(config, "tool_search_index_dir", None), DEFAULT_STORE_NAME)
+        index_dir = whoosh_dir_for_store(config.tool_search_index_dir, DEFAULT_STORE_NAME)
         if index_dir is None:
             return []
         searcher = ToolWhooshIndex(index_dir=index_dir, tuning=ToolSearchTuning.from_config(config))
-        return searcher.search(q, limit=int(getattr(config, "tool_search_limit", 20)))
+        return searcher.search(q, limit=int(config.tool_search_limit))
 
 
 class ToolPanelViewSearch:

packages/app/src/galaxy/tool_source_store

@@ -0,0 +1 @@
+../../../../lib/galaxy/tool_source_store